Analysis Of Mechanical Properties Of Double-Lap Clinching Joints And Research On Riveting-Bonded Process

The lightweight not only was an important technology to deal with environmental pollution and energy crisis,but also can help to solve the problem of manufacturing technology which caused by the weight increase of product functionalization development.At present,the best way to improve lightweight performance was to use new materials instead of traditional metals.The aluminum alloy plate,a kind of typical lightweight material,which only connected by mechanical connection technology,such as clinching,because of its poor welding performance.In this paper,the stitching behavior of 5182 aluminum alloy plate was realized by clinching.Meanwhile,the effect of adhesive layer was studied by using riveting-bonded composite technology,and the feasibility of carbon fiber adhesive riveting hybrid connection was explored.The main work completed and the research results showed as follows:(1)The double-lap clinched joints can realize the stitching behavior of aluminum alloy plate and increase the failure displacement.The influence of the position of the single butt plate on the mechanical properties of the structure is studied.The results show that the position of the butt plate has little influence on the joints strength,but the stability of the joint strength and the absorption of energy is more favorable when the position of butt plate is below.The double-lap structure can realize the connection of dissimilar materials,and the strength can be effectively improved by using a high-strength butt plate.(2)Study on riveting-bonded composite technology with 3M DP460.The results show that: Adhesives can effectively improve the strength of the clinching joints,and has better phase with the easy to yield metal.Meanwhlie,the bonding layer will change the failure mode of the inner lock structure,and the combination of double-lap structure and clinch-bonded process has the best effect.(3)The riveting-bonded composite connection between different metal bottom plates and carbon fiber plates was explored.Different from the clinch-bonded process,the strength of the adhesive layer is affected by rivets.With the decrease of the opening degree of the nail foot,the rivets tend to tilt and thus reduce the joints strength when the failure occurs.The strength of clinching is more dependent on the material properties of the upper plate,and spr is more affected by the lower plate.Among the H62,steel,TA1,H62 as the lower plate has the best phase with the spr-bonded process.The increase of the thickness of the carbon fiber plate can significantly improve the energy absorption value,but has no significant effect on the joint strength.(4)The fatigue performance of clinch-bonded composite joints was investigated.The results show that the addition of adhesive layer can change the fatigue failure mode and greatly improve the short life of the joints.During the medium and long life,the fatigue performance of the joint is correlated with the strength of the clinching.The fatigue performance of GASD in the long life is more than twice that of single point clinchbonded composite joints,indicating that the double-lap structures have outstanding advantages in the design of long or infinite life.